Lamp base



FIG. 1 is a front elevational view of a lamp base showing my new design;

FIG. 2 is a side elevational view thereof;

FIG. 3 is an opposite side elevational view thereof;

FIG. 4 is a rear elevational view thereof;

FIG. 5 is a bottom plan view thereof;

FIG. 6 is a top plan view thereof. 

The ornamental design for a lamp base, as shown. 